[PATCH 2/2] hostapd: Add DFS CAC and radar detection
Janusz Dziedzic
janusz.dziedzic
Sun Sep 15 22:40:07 PDT 2013
Add DFS CAC handling, radar detection.
By default after radar detected or
channel became unavailable random channel
will be choose.
Signed-hostap: Simon Wunderlich <siwu at hrz.tu-chemnitz.de>
Signed-hostap: Janusz Dziedzic <janusz.dziedzic at tieto.com>
---
src/ap/ap_drv_ops.c | 2 +-
src/ap/drv_callbacks.c | 21 ++++++++++
src/ap/hostapd.c | 100 ++++++++++++++++++++++++++++++++++++++++++++++--
src/ap/hostapd.h | 14 +------
src/ap/ieee802_11.c | 73 +++++++++++++++++++++++++++++++++++
src/ap/ieee802_11.h | 4 +-
6 files changed, 197 insertions(+), 17 deletions(-)
diff --git a/src/ap/ap_drv_ops.c b/src/ap/ap_drv_ops.c
index d9df9cc..cedfe8e 100644
--- a/src/ap/ap_drv_ops.c
+++ b/src/ap/ap_drv_ops.c
@@ -712,7 +712,7 @@ int hostapd_start_dfs_cac(struct hostapd_data *hapd, int freq, int flags)
return -1;
}
- if (!(hapd->iface->dfs_state & DFS_ENABLED)) {
+ if (!hapd->iface->conf->ieee80211h) {
wpa_printf(MSG_ERROR, "Can't start DFS CAC, DFS functionality "
"is not enabled");
return -1;
diff --git a/src/ap/drv_callbacks.c b/src/ap/drv_callbacks.c
index a54ab0c..68c12d2 100644
--- a/src/ap/drv_callbacks.c
+++ b/src/ap/drv_callbacks.c
@@ -788,8 +788,26 @@ static void hostapd_event_get_survey(struct hostapd_data *hapd,
static void hostapd_event_dfs_radar_detected(struct hostapd_data *hapd,
struct dfs_event *radar)
{
+ int res;
wpa_printf(MSG_DEBUG, "DFS radar detected on %d MHz", radar->freq);
+ if (!hapd->iconf->ieee80211h)
+ return;
+
+ /* mark radar frequency as invalid */
+ res = ieee802_11_set_dfs_state(hapd, radar->freq,
+ HOSTAPD_CHAN_DFS_UNAVAILABLE);
+
+ /* other frequency, just mark it and return. */
+ if (hapd->iface->freq != radar->freq)
+ return;
+
+ /* we are working on non-DFS channel - skip event */
+ if (res == 0)
+ return;
+
+ /* radar detected while operating, switch the channel. */
+ ieee802_11_start_channel_switch(hapd);
}
@@ -797,6 +815,7 @@ static void hostapd_event_dfs_cac_finished(struct hostapd_data *hapd,
struct dfs_event *radar)
{
wpa_printf(MSG_DEBUG, "DFS CAC finished on %d MHz", radar->freq);
+ ieee802_11_complete_cac(hapd, 1, radar->freq);
}
@@ -804,6 +823,7 @@ static void hostapd_event_dfs_cac_aborted(struct hostapd_data *hapd,
struct dfs_event *radar)
{
wpa_printf(MSG_DEBUG, "DFS CAC aborted on %d MHz", radar->freq);
+ ieee802_11_complete_cac(hapd, 0, radar->freq);
}
@@ -811,6 +831,7 @@ static void hostapd_event_dfs_nop_finished(struct hostapd_data *hapd,
struct dfs_event *radar)
{
wpa_printf(MSG_DEBUG, "DFS NOP finished on %d MHz", radar->freq);
+ ieee802_11_set_dfs_state(hapd, radar->freq, HOSTAPD_CHAN_DFS_USABLE);
}
diff --git a/src/ap/hostapd.c b/src/ap/hostapd.c
index 55e6c95..4af7845 100644
--- a/src/ap/hostapd.c
+++ b/src/ap/hostapd.c
@@ -932,10 +932,8 @@ static int setup_interface(struct hostapd_iface *iface)
return 0;
}
- if (iface->conf->ieee80211h) {
+ if (iface->conf->ieee80211h)
wpa_printf(MSG_DEBUG, "DFS support is enabled");
- iface->dfs_state |= DFS_ENABLED;
- }
}
return hostapd_setup_interface_complete(iface, 0);
}
@@ -946,6 +944,9 @@ int hostapd_setup_interface_complete(struct hostapd_iface *iface, int err)
struct hostapd_data *hapd = iface->bss[0];
size_t j;
u8 *prev_addr;
+ int flags;
+ struct hostapd_channel_data *channel;
+
if (err) {
wpa_printf(MSG_ERROR, "Interface initialization failed");
@@ -961,6 +962,41 @@ int hostapd_setup_interface_complete(struct hostapd_iface *iface, int err)
hostapd_hw_mode_txt(hapd->iconf->hw_mode),
hapd->iconf->channel, iface->freq);
+ /* Handle DFS channel */
+check_dfs_chan_again:
+ flags = hostapd_hw_get_channel_flag(hapd, hapd->iconf->channel);
+ if (flags & HOSTAPD_CHAN_RADAR) {
+ switch(flags & HOSTAPD_CHAN_DFS_MASK) {
+ case HOSTAPD_CHAN_DFS_USABLE:
+ wpa_printf(MSG_DEBUG, "DFS start CAC on %dMHz", iface->freq);
+ if (hostapd_start_dfs_cac(hapd, hapd->iface->freq, flags)) {
+ wpa_printf(MSG_DEBUG, "DFS start_dfs_cac() failed\n");
+ return -1;
+ }
+ /* Continue initialisation after CAC */
+ return 0;
+ break;
+ case HOSTAPD_CHAN_DFS_UNAVAILABLE:
+ wpa_printf(MSG_DEBUG, "HOSTAPD_CHAN_DFS_UNAVAILABLE, get new chan");
+ /* find other channel here */
+ channel = hostapd_dfs_get_valid_channel(hapd);
+ if (!channel) {
+ wpa_printf(MSG_ERROR, "could not get valid channel");
+ return -1;
+ }
+ hapd->iconf->channel = channel->chan;
+ hapd->iface->freq = channel->freq;
+ goto check_dfs_chan_again;
+ break;
+ case HOSTAPD_CHAN_DFS_AVAILABLE:
+ /* We don't need CAC here */
+ wpa_printf(MSG_DEBUG, "HOSTAPD_CHAN_DFS_AVAILABLE, skip CAC");
+ break;
+ default:
+ break;
+ }
+ }
+
if (hostapd_set_freq(hapd, hapd->iconf->hw_mode, iface->freq,
hapd->iconf->channel,
hapd->iconf->ieee80211n,
@@ -1477,3 +1513,61 @@ void hostapd_new_assoc_sta(struct hostapd_data *hapd, struct sta_info *sta,
eloop_register_timeout(hapd->conf->ap_max_inactivity, 0,
ap_handle_timer, hapd, sta);
}
+
+static int hostapd_dfs_find_channel(struct hostapd_data *hapd,
+ struct hostapd_channel_data **ret_chan,
+ int idx)
+{
+ struct hostapd_hw_modes *mode;
+ struct hostapd_channel_data *chan;
+ int i, channel_idx = 0;
+
+ mode = hapd->iface->current_mode;
+
+ for (i = 0; i < mode->num_channels; i++) {
+ chan = &mode->channels[i];
+
+ if (chan->flag & HOSTAPD_CHAN_DISABLED)
+ continue;
+
+ if (chan->flag & HOSTAPD_CHAN_RADAR &&
+ chan->flag & HOSTAPD_CHAN_DFS_UNAVAILABLE)
+ continue;
+
+ if (ret_chan && idx == channel_idx) {
+ wpa_printf(MSG_DEBUG, "Selected ch. #%d", chan->chan);
+ *ret_chan = chan;
+ return idx;
+ }
+ channel_idx++;
+ }
+ return channel_idx;
+}
+
+struct hostapd_channel_data * hostapd_dfs_get_valid_channel(
+ struct hostapd_data *hapd)
+{
+ struct hostapd_hw_modes *mode;
+ struct hostapd_channel_data *chan = NULL;
+ int channel_idx, new_channel_idx;
+ u32 _rand;
+
+ wpa_printf(MSG_DEBUG, "DFS: Selecting random channel");
+
+ if (hapd->iface->current_mode == NULL)
+ return NULL;
+
+ mode = hapd->iface->current_mode;
+ if (mode->mode != HOSTAPD_MODE_IEEE80211A)
+ return NULL;
+
+ /* get random available channel */
+ channel_idx = hostapd_dfs_find_channel(hapd, NULL, 0);
+ if (channel_idx > 0) {
+ os_get_random((u8 *) &_rand, sizeof(_rand));
+ new_channel_idx = _rand % channel_idx;
+ hostapd_dfs_find_channel(hapd, &chan, new_channel_idx);
+ };
+
+ return chan;
+}
diff --git a/src/ap/hostapd.h b/src/ap/hostapd.h
index b5595e7..379dd8d 100644
--- a/src/ap/hostapd.h
+++ b/src/ap/hostapd.h
@@ -315,18 +315,6 @@ struct hostapd_iface {
/* lowest observed noise floor in dBm */
s8 lowest_nf;
-
- /* DFS functionality is enabled. */
-#define DFS_ENABLED BIT(0)
-
- /* DFS channel availability check during initialization. */
-#define DFS_CAC_ACTIVE BIT(1)
-
- /* DFS channel availability check completed successfully. */
-#define DFS_CAC_SUCCESS BIT(2)
-
- u8 dfs_state; /* DFS_* bitfield */
-
#ifdef CONFIG_ACS
unsigned int acs_num_completed_scans;
#endif /* CONFIG_ACS */
@@ -392,4 +380,6 @@ const struct hostapd_eap_user *
hostapd_get_eap_user(struct hostapd_data *hapd, const u8 *identity,
size_t identity_len, int phase2);
+struct hostapd_channel_data * hostapd_dfs_get_valid_channel(
+ struct hostapd_data *hapd);
#endif /* HOSTAPD_H */
diff --git a/src/ap/ieee802_11.c b/src/ap/ieee802_11.c
index 781f826..52bb5d0 100644
--- a/src/ap/ieee802_11.c
+++ b/src/ap/ieee802_11.c
@@ -2239,5 +2239,78 @@ void ieee802_11_rx_from_unknown(struct hostapd_data *hapd, const u8 *src,
WLAN_REASON_CLASS3_FRAME_FROM_NONASSOC_STA);
}
+int ieee802_11_set_dfs_state(struct hostapd_data *hapd, int freq, u32 state)
+{
+ struct hostapd_hw_modes *mode;
+ struct hostapd_channel_data *chan = NULL;
+ int i;
+
+ mode = hapd->iface->current_mode;
+ if (mode == NULL)
+ return 0;
+
+ if (mode->mode != HOSTAPD_MODE_IEEE80211A) {
+ wpa_printf(MSG_WARNING, "current_mode != IEEE80211A");
+ return 0;
+ }
+
+ for (i = 0; i < hapd->iface->current_mode->num_channels; i++) {
+ chan = &hapd->iface->current_mode->channels[i];
+ if (chan->freq == freq) {
+ if (chan->flag & HOSTAPD_CHAN_RADAR) {
+ chan->flag &= ~HOSTAPD_CHAN_DFS_MASK;
+ chan->flag |= state;
+ return 1; /* Channel found */
+ }
+ }
+ }
+ wpa_printf(MSG_WARNING, "Can't set DFS state for freq %d MHz", freq);
+ return 0;
+}
+
+int ieee802_11_complete_cac(struct hostapd_data *hapd, int success, int freq)
+{
+ struct hostapd_channel_data *channel;
+ int err = 1;
+
+ if (success) {
+ /* Complete iface/ap configuration */
+ ieee802_11_set_dfs_state(hapd, freq, HOSTAPD_CHAN_DFS_AVAILABLE);
+ hostapd_setup_interface_complete(hapd->iface, 0);
+ } else {
+ /* Switch to new channel */
+ ieee802_11_set_dfs_state(hapd, freq, HOSTAPD_CHAN_DFS_UNAVAILABLE);
+ channel = hostapd_dfs_get_valid_channel(hapd);
+ if (channel) {
+ hapd->iconf->channel = channel->chan;
+ hapd->iface->freq = channel->freq;
+ err = 0;
+ } else
+ wpa_printf(MSG_ERROR, "No valid channel available");
+
+ hostapd_setup_interface_complete(hapd->iface, err);
+ }
+
+ return 0;
+}
+
+int ieee802_11_start_channel_switch(struct hostapd_data *hapd)
+{
+ struct hostapd_channel_data *channel;
+ wpa_printf(MSG_DEBUG, "%s called\n", __func__);
+ int err = 1;
+
+ channel = hostapd_dfs_get_valid_channel(hapd);
+ if (channel) {
+ hapd->iconf->channel = channel->chan;
+ hapd->iface->freq = channel->freq;
+ err = 0;
+ }
+
+ hapd->driver->stop_ap(hapd->drv_priv);
+
+ hostapd_setup_interface_complete(hapd->iface, err);
+ return 0;
+}
#endif /* CONFIG_NATIVE_WINDOWS */
diff --git a/src/ap/ieee802_11.h b/src/ap/ieee802_11.h
index 2aab56d..358edfd 100644
--- a/src/ap/ieee802_11.h
+++ b/src/ap/ieee802_11.h
@@ -80,5 +80,7 @@ u8 * hostapd_eid_time_zone(struct hostapd_data *hapd, u8 *eid);
int hostapd_update_time_adv(struct hostapd_data *hapd);
void hostapd_client_poll_ok(struct hostapd_data *hapd, const u8 *addr);
u8 * hostapd_eid_bss_max_idle_period(struct hostapd_data *hapd, u8 *eid);
-
+int ieee802_11_complete_cac(struct hostapd_data *hapd, int success, int freq);
+int ieee802_11_set_dfs_state(struct hostapd_data *hapd, int freq, u32 state);
+int ieee802_11_start_channel_switch(struct hostapd_data *hapd);
#endif /* IEEE802_11_H */
--
1.7.9.5
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